If you don't want a MASSIVE exit wound, a lot of the loads recommended above would not be a good idea. Hornady makes a special "SX" 50 gr .22 softpoint, intended to not exit. I would suggest an AR-15, so you can take several shots at several yotes, or at one that is running. I might even consider using tracers, under certain conditions, but that might be illegal in some states, dunno. The AR-15 would give the option of shooting matches (BE or combat) as well as being a shtf or defensive, gun. With a $150 Ciener .22lr conversion unit, its a fine small game gun, and a great trainer for novices. For use in a prairie dog town, it is the primo choice, because many hundreds of shots won't heat it up enough to cause heat mirage enough to make you miss at 100 yds, as happens with all bolt actions. The 40 gr Federal hp is unlikely to exit, and is available as a loaded rd. So is a 45 gr load at Wally's, Winchester, IIRC? I use only 60 gr Nosler Partition Softpoints, but I don't care about the pelt. The partition gets deep penetration, for deer and men